You’ve had it happen to you before: you're in a dark room with nothing but your smartphone, and as soon as you switch it on to check your email, your eyes are quickly regretting that decision. Turning on that smartphone was like taking off your sunglasses and staring directly in the sun. You might then turn down the brightness on your phone for a later time, but the device is still using a ton of power to output that light. Smartphones can use as much as fifty percent of the total phone power just to light up that LCD display, draining its precious battery.